Apparatus for burning spirit and similar liquid fuels

ABSTRACT

The present invention relates to an apparatus for burning liquid fuel in which a fuel container is filled with a fuel absorptive mass in which is provided a vertical burner channel in which burning of fuel evaporated from an exposed surface of the absorptive mass defining the channel takes place with supplied air.

United States Patent Inventor Karl Oskar Arne Boij Verkstadsgatan, 573 00 Tranas, Sweden Appl. No. 549 Filed Jan. 5, 1970 Patented Dec. 14, 1971 Priority Jan. 14, 1969 Sweden 426/69 APPARATUS FOR BURNING SPIRIT AND SIMILAR LIQUID FUELS 3 Claims, 3 Drawing Figs.

US. Cl 431/326 Int. Cl F23d 3/40 Field of Search 431/326 [56] References Cited UNITED STATES PATENTS 421,543 2/1890 Bonhack et al. 431/326 614,034 11/1898 Stewart 431/326 1,819,363 8/1931 Fernandez et a1. 431/326 X FOREIGN PATENTS 89,633 10/1921 Switzerland 431/326 Primary Examiner--Carroll B. Dority, Jr. A!t0rneyFred C. Philpitt ABSTRACT: The present invention relates to an apparatus for burning liquid fuel in which a fuel container is filled with a fuel absorptive mass in which is provided a vertical burner channel in which burning of fuel evaporated from an exposed surface of the absorptive mass defining the channel takes place with supplied air.

APPARATUS FOR BURNING SPIRIT AND SIMILAR LIQUID FUELS The present invention relates to such apparatus for burning spirit and similar liquid fuels, in which the fuel container is filled with a fuel absorptive, preferably fibrous mass in which is provided a preferably vertical burner channel in which burning or fuel evaporated from the exposed surface of the absorptive mass defining the channel takes place with supplied air.

In previous known apparatus of the kind referred to above the combustion air has been supplied to the burner channel provided in the absorptive mass either through the lower opening of the channel or through a separate pipe opening into the channel at the bottom thereof, meaning that a separate opening for air supply must be provided in the wall of the fuel container. Said drawback has been eliminated by the present invention according to which combustion air is supplied to the burner channel from above through an annular gap formed between a suction or burner pipe inserted from above and surrounding wall of the burner channel. The mixture of air introduced through the annular gap and fuel evaporated from the wall of the burner channel is combusted in the burner channel and the flame formed is sucked from the burner channel upwards through the suction pipe, at the opening of which final combustion takes place in the form of an open flame. The dimensions and the burning intensity, respectively, of the open flame is determined by the amount of evaporated fuel per unit of time, and said amount is, inter alia, dependent on the vertical extension of the zone being swept over by the air sucked in through the annular gap, so that within certain limits the dimensions of the flame will be larger when the suction pipe is pushed further down into the burner channel. According to a preferred embodiment of the invention the suction pipe is made adjustable in a vertical direction so as to permit the dimensions of the flame to be adjusted through axial displacement of the suction pipe, but it is also possible to secure the suction pipe in a selected rigid position in the burner channel.

The invention will now be described more in detail with reference to the accompanying drawings, which schematically show an embodiment of the invention with the suction pipe in three different vertical positions.

In the drawings:

FIG. 1 shows the suction pipe inserted fairly deep down into the burner channel, resulting in an open flame of maximum size.

FIG. 2 shows the suction pipe in a position only slightly within the burner channel, resulting in an open flame of reduced size.

FIG. 3 shows the suction pipe in an uppermost position entirely outside of the suction channel, the flame in this case being so small that it is housed entirely within the suction pipe.

In the drawings, numeral designates a closed fuel container in the form of a circular box in the top wall of which there is centrally provided a circular opening 11. The box is filled with a fuel absorptive material consisting of two circular sheets 12 of mineral wool or the like and a circular sheet 13 of glass wool inserted between the sheets of mineral wool. Centrally through the filling l2, 13 of fuel absorptive material there is provided a vertical cylindrical burner channel 14 extending to the opening 11 in the top wall of the fuel container. Between the top wall of the container and the fuel absorptive filling is inserted a venting net 15 of metal. A suction or burner pipe 16, the outer diameter of which is smaller than the inner diameter of the burner channel 14, is according to the invention inserted centrally into the burner channel 14, so that an annular gap 17 is formed between the suction pipe in its inserted position and the surrounding wall of fuel absorptive filling. At the bottom of the fuel container there is provided a sheet 18 of asbestos paper or the like serving as a heat radiation screen.

The combustion starts in the gap 17 and the flame, after having swept over the wall of the burner channel, is sucked u wards through the suction pipe 16 at the upper ofpening of w ich final combustion takes place in the form 0 an open flame 19. As is seen from the drawing figures, the dimensions of the flame 19 will increase with the extension in a vertical direction of the zone of the wall of the burner channel 14 which is swept over by the air sucked in through the annular gap 17, ie the dimensions and the intensity, respectively, of the flame increases within certain limits when the suction pipe 16 is inserted further into the burner channel 14. Preferably, the apparatus is provided with a mechanism for axial displacement of the suction pipe 16 to permit adjustment of the intensity of the combustion, but it is also possible to secure the suction pipe rigidly in a position ensuring a certain desired volume of flame.

In certain burners it may be desirable to screen off a portion of the exposed evaporating surface of the burner channel 14. Said screening may, for instance, consist of a rigid or movable pipe inserted in the burner channel. By exposing only an insignificant portion of the absorptive mass the glow at the final combustion of the fuel can be reduced, ensuring in such a manner a less amount of carbon monoxide, this being desirable if the burner is used in connection with stoves. Particularly in this kind of burner it may be preferable to adjust the supply of combustion air and the burning efiect by means of a draught valve disposed around the burner pipe instead of by moving the burner pipe upwards or downwards in the burner channel.

The burner apparatus may, of course, be completed in different respects, e.g. by being provided with a flame spreader and a cover or the like for extinguishing the flame.

What I claim is:

1. An apparatus for burning spirit or similar liquid fuels wherein the fuel container is filled with a fuel absorptive mass in which is provided a preferably vertical burner channel with an entirely or partly exposed surface from which the fuel to be burnt is evaporated, characterized by a suction or burner pipe which forms an extension upwards of the burner channel and is dimensioned and positioned relative to said channel in such a manner that an annular gap permitting the sucking in of combustion air is formed between said burner channel and said suction pipe.

2. An apparatus as claimed in claim 1, characterized in that the cross-dimensions of said suction pipe are smaller than those of the burner channel and that said suction pipe is inserted somewhat into said burner channel, so that the annular gap is formed between the outer side of the pipe and the wall of the burner channel.

3. An apparatus as claimed in claim 1, characterized in that the suction pipe is adjustable to different vertical positions relative to the burner channel to the end of adjusting the dimensions of the flame.

i i t i t 

1. An apparatus for burning spirit or similar liquid fuels wherein the fuel container is filled with a fuel absorptive mass in which is provided a preferably vertical burner channel with an entirely or partly exposed surface from which the fuel to be burnt is evaporated, characterized by a suction or burner pipe which forms an extension upwards of the burner channel and is dimensioned and positioned relative to said channel in such a manner that an annular gap permitting the sucking in of combustion air is formed between said burner channel and said suction pipe.
 2. An apparatus as claimed in claim 1, characterized in that the cross-dimensions of said suction pipe are smaller than those of the burner channel and that said suction pipe is inserted somewhat into said burner channel, so that the annular gap is formed between the outer side of the pipe and the wall of the burner channel.
 3. An apparatus as claimed in claim 1, characterized in that the suction pipe is adjustable to different vertical positions relative to the burner channel to the end of adjusting the dimensions of the flame. 